Be Smart. Know Your Hazard

Tornadoes are one of nature’s most violent storms, and can cause death, injury, and destruction within seconds. For more information, download the How to Prepare for a Tornado guide, which provides the basics of tornadoes, explains how to protect yourself and your property, and details the steps to take now so that you can act quickly when you, your home, or your business is in danger.

Tornado Basics

WHAT: A tornado is a violently rotating column of air that extends from a thunderstorm to the ground and is often—although not always—visible as a funnel cloud. Lightening and hail are common in thunderstorms that produce tornadoes.

WHEN: Tornadoes can strike in any season, but occur most often in the spring and summer months. They can occur at all hours of the day and night, but are most likely to occur between 3 p.m. and 9 p.m.

WHERE: About 1,200 tornadoes hit the United States every year and every state is at risk. Most tornadoes in the United States occur east of the Rocky Mountains.

Know the Risk

Do you want to have a better understanding of the tornado risk you and your community face? Below is a map of the United States and the frequency of tornadoes rated F3/EF3 or higher in your county since 1996.

Map Information:The map is titled, “Tornado Activity by County: 1996-2013.” It depicts a map of the continental United States, Puerto Rico, Alaska, and Hawaii including state boundaries. It includes data from the NCDC Storm Events Database. All tornadoes classified as F0-F5 or EF0-EF5 are included. F-scale and EF-scale tornadoes are grouped as equivalent for consideration of frequency categories.Map description: The frequency of tornadoes from 1996 to 2013 is represented by four categories.The first category includes counties that have recorded the highest frequency of F3 or EF3 or stronger tornadoes or from four to seven (4-7) tornadoes at the F3 or EF3 or greater level. The areas of the United Stated in this category include from one to several counties in Nebraska, Kansas, Oklahoma, Arkansas, Tennessee, Mississippi, and Alabama.The second category includes counties that have recorded the second highest frequency of F3/EF3 or stronger tornadoes or from one to three (1-3) tornadoes at the F3 or EF3 or greater level. The areas of the United States in this category include one or more counties in Arizona, Montana, North Dakota, South Dakota, Nebraska, Colorado, Kansas, Oklahoma, Texas, Louisiana, Arkansas, Missouri, Iowa, Minnesota, Wisconsin, Illinois, Kentucky, Tennessee, Mississippi, Alabama, Indiana, Michigan, Ohio, New York, Pennsylvania, Maryland, Virginia, North Carolina, South Carolina, Georgia, and Florida. The area with coverage by this category goes from north to south from North Dakota and Minnesota on the north to Texas, Louisiana, Mississippi, and Alabama on the south including the states in between. There is a second area of this category that goes from west to east from Kansas and Oklahoma on the west side, through Arkansas, Tennessee and Mississippi to Alabama and Georgia on the east.The third category includes counties where the largest recorded tornado has been at the F2 level or below (levels EF2, EF 1 or EF0). The states with counties in this category include most or all of every state not previously listed in the states with higher level tornadoes and Puerto Rico.The fourth and last category includes counties with no recorded tornadoes. States with counties in this category include most of Alaska, West Virginia, and Puerto Rico, areas of several counties in Washington state, Oregon, California, Idaho, Utah, Nevada, Arizona, Montana, Wyoming, Colorado, New Mexico, Nebraska, Texas, and Vermont, and small areas of South Dakota, Nebraska, Minnesota, Missouri, Wisconsin, Michigan, Indiana, Ohio, Kentucky, Tennessee, Louisiana, Maine, Massachusetts, New York, Pennsylvania, New Jersey, Virginia, North Carolina, Georgia, and Florida. Overall, most of the US is included in one of the first three categories that have had some level of recorded tornado.Federal Emergency Management AgencyORR Mapping and Analysis Center, Washington, D.C., March 13, 2014. Sources: ESRI, USGS.

Additional Resources

For more information on protecting yourself from a tornado and protecting your property and belongings, download these helpful resources:

Be Smart-Know Your Alerts and Warnings: The factsheet provides a brief summary of the various alerts and warnings available from Federal, state, local governments as well as the private sector that you can sign up for to stay informed and be ready to take action to be safe.